Smolt Tracking Report Shows Interesting Results

The smolt tagging and tracking project is a three year programme of work. Fifty smolts, captured in the lower catchment, were fitted with internal acoustic tags and tracked in spring 2016. These smolts were tracked as they migrated through the lower 22 miles of the Dee and inner harbour.

We completed the first year of our three year smolt tagging and tracking project in July of this year and since then Dr Lorraine Hawkins has been busy analysing the masses of data this work produced. We are pleased to share our findings and hope you find the accompanying report of interest and value.

Lorraine said, “2016 was our ‘pilot’ year and it has been a steep learning curve for the team as we got to grips with new equipment and the delicate process of fitting internal acoustic tags. I am very pleased with how it has gone and we now have an interesting set of results regarding the timing and speed of migration, but also some interesting results on mortality.

We had anticipated mortality in the inner harbour area, but were surprised to find that 26% of tagged smolts died in the river, with none dying in the inner harbour. While we can’t draw any firm conclusions about this, we believe it is caused by either predation or delayed effects from the tagging process. The 2016 findings will inform and guide our efforts in 2017 and 2018. We are particularly keen to find out more about in-river mortality as it may be something we can mitigate against.”

​With the news and social media rife with the invasion of Pacific pink salmon, we want to give people an update on the situation on the Dee and what we are doing about it. The situation has developed rapidly in the last month.

As a charity, the River Dee Trust has to raise funds to support its work on the River Dee. We have been humbled by the level of support throughout the year. In the last couple of months, we have had two fundraising events, which have raised £11500, all thanks to the community and River Dee family.

Tackling invasive non-native plants along the banks of the River Dee – such as Japanese knotweed, giant hogweed, Himalayan balsam and North American skunk cabbage - has become a priority for the River Office because of their potential impact on our river and its existing, native species.